The present invention relates to devices for infusing, delivering, administering, injecting or dispensing a substance, and to methods of making and using such devices. More particularly, it relates to an arrangement for introducing a liquid into the body of a patient or for withdrawing a liquid from the body of a patient and use of the arrangement for subcutaneous supplying of a liquid medicament into the body of a patient.
In those patients who have an ongoing need for medicaments or therapeutic agents to be administered by direct supply to the body tissue or the blood stream, or in whom body fluid samples for monitoring certain parameters, such as e.g. blood sugar, need to be taken from the body over a longer period, it is meaningful to undertake supply of the medicament or withdrawal of the body fluid via a cannula introduced at a suitable site into the body and remaining there over a longer period.
For example, these days, in many patients with type I and type II diabetes, the required quantity of insulin is supplied to the body continuously or at short intervals. This may be accomplished, in many instances, using a cannula inserted through the skin into the subcutaneous tissue of the patient, which is part of an arrangement attached to the body of the patient and often designated as an “infusion set.” The insulin supplied is controlled by an automated insulin pump. The connection between insulin pump and infusion set is made by a flexible supply conduit which is coupled detachably to the infusion set by a connector. Since the infusion set is worn practically permanently on the body, good wearer comfort is important. For this reason, the infusion set is built as flat as possible, including with a supply conduit connected, and the freedom of movement of the patient is impaired to the least extent possible. In addition, it is important that the coupling and uncoupling of the supply conduit can be done easily and securely and operating errors are excluded as early as possible by the constructive configuration of the infusion set. Similar marginal conditions and requirements will emerge when body fluid samples are taken from the body of a patient over a longer period.
Documents WO 02/070037 A2, DE 299 05 068 U1, U.S. Pat. No. 6,923,791 B2, WO 2005/049117 A2, US 2005/0101910 A1 and WO 2004/026375 A1 disclose infusion devices in which the supply conduit with an adapter part in an axial direction of the cannula can be set on the part of the device bearing the cannula and can be removed again from the latter in the opposite direction. The cannula in the infusion devices disclosed in WO 02/070037 A2, U.S. Pat. No. 6,923,791 B2, WO 2005/049117 A2, US 2005/0101910 A1 and WO 2004/026375 A1 are provided for substantially vertical insertion into the body of the patient, whereby the supply conduit is led away from the adapter part in a direction vertical to the direction of setting. The device disclosed in DE 299 05 068 U1 is provided for inserting into the body of a patient at a flat angle, whereby the supply conduit is led away from the adapter part in the direction of setting. After being set on the part bearing the cannula, the adapter part in the devices according to WO 02/070037 A2, DE 299 05 068 U1, U.S. Pat. No. 6,923,791 B2, WO 2005/049117 A2, US 2005/0101910 A1 is rotatable relative to the part bearing the cannula, while in the device disclosed in WO 2004/026375 A1 it is latched in rotatory alignment selected for setting on with respect to the part bearing the cannula.
A disadvantage of known devices is that the adapter for uncoupling the supply conduit from the infusion set in the axial direction of the cannula is removed from the infusion set, whereby there is a not insubstantial danger that the cannula may be withdrawn from the injection site unnoticed fully or partially, resulting in no delivery or inadequate delivery of liquid medicament into the tissue.
A further disadvantage of the infusion devices disclosed in WO 02/070037 A2, U.S. Pat. No. 6,923,791 B2, WO 2005/049117 A2, US 2005/0101910 A1 and WO 2004/026375 A1 is that, in the applied state with the supply conduit coupled, they have a relatively high structure. An added disadvantage of the device disclosed in DE 299 05 068 U1 is that after application of the part bearing the cannula on the body of a patient there is no further possibility of altering the direction in which the supply conduit leads away from the infusion device.